All-perovskite tandem solar cells with dipolar passivation
Article Date: 27 October 2025
Article URL: https://www.nature.com/articles/s41586-025-09773-7
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Summary
The authors report a dipolar passivation strategy for buried interfaces in lead–tin (Pb–Sn) narrow-bandgap (NBG) perovskite subcells that both reduces trap density and precisely tunes energy-level alignment at the hole-transport-layer (HTL)/perovskite interface. Unlike long-chain amine passivation that can impede carrier transport, the dipolar layer improves ohmic contact for holes while repelling electrons from the interface. The result is a dramatic increase in carrier diffusion length (measured up to 6.2 μm) and strong device performance: a single Pb–Sn perovskite cell reached 24.9% PCE (VOC 0.911 V, JSC 33.1 mA cm−2, FF 82.6%). Implementing the dipolar passivation in all-perovskite tandems yielded an outstanding PCE of 30.6% (certified stabilized 30.1%), largely by mitigating interconnect-induced contact losses in the NBG subcell.
Key Points
- Dipolar passivation reduces trap states at the buried HTL/Pb–Sn perovskite interface while enabling precise energy-level alignment.
- The method promotes ohmic hole contact and repels electrons, avoiding carrier-transport losses common with long-chain amine passivants.
- Carrier diffusion length extended to ~6.2 μm, improving charge collection and reducing non-radiative recombination.
- Single Pb–Sn narrow-bandgap cell reached 24.9% PCE with VOC 0.911 V, JSC 33.1 mA cm−2 and FF 82.6%.
- All-perovskite tandem devices achieved 30.6% PCE (certified stabilised 30.1%), showing the approach tackles contact losses in stacked architectures.
- Supplementary materials show molecular adsorption dynamics (NH3+ and SO3− terminated species) that underpin the dipolar behaviour.
Context and relevance
Perovskite tandems are one of the fastest-moving routes to >30% solar-cell efficiencies, but buried-interface recombination — especially in Pb–Sn narrow-bandgap cells — has been a persistent barrier. This paper offers a materials-level solution that simultaneously passivates traps and engineers interface energetics without the transport penalties of previous passivation chemistries. That dual effect is exactly what’s needed to push laboratory tandem devices closer to commercially relevant performance and stability benchmarks.
Why should I read this
Short version: this is clever, practical interface engineering that fixes a real bottleneck for perovskite tandems. If you care about getting perovskite-based tandems past lab curiosity and towards consistently high efficiencies, the dipolar passivation trick is worth your attention — it lifts both carrier lifetime and contact quality, and the certified 30.1% stabilised tandem result speaks for itself.